Automobile chassis frame and method of making same



Jan. 30, 1 H, .CROWE 1,945,505

AUTOMOBILE CHASSIS FRAME AND METHOD OF MAKING SAME Filed Sept. 19, 193114 Fg! 4 .A j? rgal /.'V VENTOR fa/Vas /f Ron/f BY MA, M,

A TYOR/VE V Patented Jan. 30, 1934 PATENT@ OFFICE AUTOMOBILE CHASSISFRAME. AND

METHOD 0F MAKING SAM James H. Crowe, Cleveland, Ohio, assignof .c TheMidland' Steel. Products Company, Cleveland, Ohio, a corporation of OhioApplication September 19, 1931 Serial No. 563,773'

10`l Claims.

This invention relates to new and useful improvements in automobileYchassisframes.

An important object of theinvention is` to provide a chassis frame ofrequisite strength and elastic limit having a portion thereof capable ofhaving a body finish and polish imparted thereto byY the usual methodsemployed for imparting finish and polish to the metal body platesconstituting the shell of an automobile body, whereby these portions ofthe chassisframe can be exposed toviewl as part of the exterior bodyappearance to take the place of adjuncts of the body such as the dustshields above the running boards; thus eliminating the usual expense ofsuch separate parts.

Another'important object is to provide a chassis frame having side railsprovided with kick-ups or offsets at the ends thereof and whichv can bemanufactured without the usual waste of material represented in scrap orthe necessity of edgewise bending to produce the kicked-up portions.

Another object of the invention is to provide a side rail including acold rolled section to which may be imparted the requisite finish byusual finishing methods.

A still further object of the invention is to provide a method of makinga chassis sideV rail consisting of cutting a plurality of separateblankedout strips of any desired shape from strips of stock widths andbutt-welding. the same end to end to provide a blank of requisite shapewhich is then formed into a channel section possessing the necessaryelastic limit and a portion of which will take a finish orpolishequivalent to that of the body shell by methods now employed forfinishing the latter.

A further object of the invention is to produce a chassis frame whichwill possess, in addition to the foregoing characteristics, an. elastic.limit of at least 40,000 pounds per square inch as econom ically aspossible, using for the major part thereof, mild carbon steel of theformula S. A. E. 1025 and a lower carbon steel for certain sectionsthereof.

Other objects and advantages of the invention will become apparentduring the course of the following description.

In the accompanying drawing forming` a part of the descriptive matterand wherein like numerals are employed to designate like partsthroughout the several views.

Fig. 1 is a plan of a stock size width of steel strip as it comes fromthe mill, the dotted lines indicating the manner of blanking outsuitably (Cl.l 280--106) shaped blanks used in the formation of thefront portions of side rails.

Fig. 2 is asimilar view of a strip of pickled cold-rolled steel having acarbon content in the range of. .10 %-.25% as it comes from the mill,the dotted line showing the manner o-fblanking out the intermediatesections of the side rails.

Fig. 3 is a similar view of a strip of steel as it cornes from the mill,the dotted lines indicating the manner of blanking out the sections'forming the rear ends of the side rails with the minimum amount ofscrap.v

` Fig. 4 is av plan of a fiat blank composed of a blanked out sectionfrom each of the three preceding figures, the meeting4 end edges of thethree blanks being integrally united preferably by buttwelding.

5 is a side elevation of a portion of an automobile showing the improvedchassis frame construction forming a part thereof.

Fig. 6 is an enlarged transverse section of the same taken on the line6-6 of Fig. 5. Y

Heretofore it has been the general practice to form each side rail of anautomobile chassis frame from a single blank of sheet steel integralthroughout its entire length.` When such frames are to possess a doubledrop or kick-up, portions are to be disposed above the front and rearaxles of` the vehicle for the purpose of lowering the center of gravityof the vehicle, it is necessary to either cut the single blankformingthe side rail to they requisite shape, resulting in severe wasteby reason of the scrap incident thereto, or by the process known asedgewise bending of the straight flat blank prior to its formation intothe customary channel cross section. This latter procedure of edgewisebending is unsuitable for the purposes of this invention inasmuch as itresults, in some instances, in producing ripples or waves in the regionswhere thev laterally offset portions to produce the kick-ups, merge intothe intermediate portion of the side rail, and moreover, subjects theblanks to two series of stresses acting substantially at right angles toeach other, the rst resulting from the edgewise bending and the secondstresses resulting from the formation of the flat blank into channelsection resulting frequently in the rupture or cracking of the siderails and a material weakening of the same at the points of greateststress. As indicated previously, such edgewise bending would be unsuitedfor the purposes of this invention inasmuch as it would be apt toproduce ripples or cracks in the intermediate portion of the side railwhich it is proposed to REHSSMQED shields or aprons disposed above therunningl boards, each side rail is composed of three component parts orsectionsbutt-welded or secured in any other suitable manner to form anintegral wholeQ Such a blank or strip, prior to formation into a channelsection, is illustrated in Fig. 4, as composed of a front section orblank '7, an intermediate blank 8 and a rear blank or section 9. Thefront and rear blanks 7 and 9 are blanked to shape to provide thekicked-up lportions 10 and 11 respectively from stock-width blanks 12and 13 respectively, shown in Figs. 1 and 3. These strips 12 and 13 aresteel strips of requisite gauge as it comes from the mill manufacturedunder any suitable formula but preferably under the formula S. A. E.1025 possessing carbon in the amount of from .20%.30%. Steel of thischaracter inran untreated condition will allow for an elastic limit ofat least 40,000 pounds per square inch as required by the automotivemanufacturers. These strips of stock material are of su'icient width topermit of the sections 7 and 9 being blanked from the same, transverselythereof and indicated in Figs. 1 and 3 with very little scrap lossindica-ted by the portions marked 14.

As will be obvious, the maximum scrap results from the production of thefirst and last blanks cut/from the strip and only a small amount ofscrap results from the production of the intermediate blanks or sections7 and 9. However,

' untreated stock material of the foregoing character ordinarily used inthe construction Vof automobile chassis frames cannot be given a bodyfinish and polish substantially equivalent to the exterior body finishof the ordinary automobile without the use of expensive grinding andpolishing equipment and the use of special fillers and lacquers, therebyrunning the cost of production of a chassis frame from the usualmaterials and the aforesaid equipment so high as to be practicallyprohibitive.

I have found that the purposes of this invention can be accomplished bythe use of special material for the intermediate sections 8 which willtake on a body finish from the usual methods of finishing body platesfor the body shell of the automobile and at the saine time will possessthe requisite elastic limit to anticipate manufacturers specificationsand requirements.

While not desiring to be limited to any particular material for thispurpose it has been found that the object of this invention can beadmirably accomplished by the use of pickled, cold rolled, or rustlesssteel having a carbon content somewhere close to the range.` o-f .10% upto possibly .25%. Such quality of material is represented in a strip ofstock width designated by the numeral l5 in Fig. 2 which may be blankedto shape to form the individual blanks or sections 8 by cutting thestrip along the dotted lines 16 transversely of the longitudinaldimensions of the strip. Preferably, however, these straight sectionsare produced from a roll of cold-rolled strip to take the place of otheradjuncts or to present 'a more finished appearance for the portionsoil.,

carried in stock and having a width equal to the width of the blank 8.In this manner, the blanks 8 can be produced by simply cutting the striptransversely of its length in lengths equal to the length of suchblanks. The shape of the intermediate blanks is such that there is nowaste by scrap, or very little if requirements call for the blankshaving slightly deflected longitudinal edges.

After the blanks 7, 8 and 9 have been blanked f to any desired shapethey are placed in longitudinal alignment in the order named with theirtransverse end edges 17 and 18 arranged in abutting relationship to beunited, preferably by butt-welding to form the welded seams 19 whichtend to increase the strength of the side rail against tension andcompression as well as to have a tendency to minimize torsionalstresses. The union of these three separate and independent blanks formssubstantially a one piece blank or strip of the requisite shapepossessing the necessary characteristics hereinbefore mentioned. 'Incase butt-welding is used, the flash is removed from the exteriorsurface of the blank comprising the united sections '7, 8 and 9,. afterwhich it is then cold formed into a channel section having throughoutits entire length a web portion 20 and upper and lower inwardlyextending horizontal ianges 21 and 22 respectively. If desired, each ofthe individual blanks 7, 8 and 9, prior to their being united into asingle blank, may be formed into individual channel sections andsubsequently united by butt-welding or otherwise, the meeting edges ofthe webs and horizontal anges of the individual sections along thevertical seams 19. However, it is more economical to unite theindividual blanks '7, 8 and 9 prior to their formation into a channelside rail. The exterior surface of the web of the section 8 may besubsequently provided with a body finish and polish equal to that'of theexterior nish of an automobile body by the usual methods of fin- .1

ishing and polishing the body plates or shell.

By reason of the foregoing, the usualv dust shield or apron heretoforeemployed in automobile body construction above the running board 23, maybe dispensed with, since the exposed exterior surfaces of the web of theintermediate section 8 of the side rail may be provided with a finishequivalent to that of the exterior surface of the automobile body 24.The running boards may be secured to the chassis framein any suitf ablemanner, although as here shown, they are attached to the side rails bymeansof step hangers or the angle bars 25. Portions 26 .and.27,respectively of the front and rear mud guards cover the seams betweenthe sections 7, 8 and 9 of the side rails thereby presenting a finishedsurface with no exposed rivets or other form of fastening means. Byreason of the foregoing construction and arrangement of parts,` two ofthe heretofore necessary adjuncts of the automobile ,1.1;

body have been eliminated without sacrificing the elastic limits of thechassis frame, and the scrap incident to the manufacture of thisinvention has been reduced to the very minimum. While the invention hasbeen illustrated in connection `with the intermediate portions of theside rails forming dust shields, it is to be understood, that I do notlimit the invention to this particular adjunct, other than in theappended claims, since parts of the frame, other than the intermediatesection 8, may be provided with such body finish to be exposedexteriorly of the automobile body the frame which are exposed to view inthe nished automobile.

Due to the fact that the side rails are composed of a plurality ofsections, one or more of such sections can be made of different gaugematerial, i. e. the intermediate section 8 where the greater portion ofthe body loads are imposed may be of heavier gauge than the end sections'7 and 9, or the latter may be of thicker gauge than the intermediatesection. Likewise, these component sections of the rails may be ofdifferent metallurgical analysis and of various cross-sectional shapesthan that illustrated. Also, the component parts of each side rail maybe of different cross sectional shape. For instance the intermediatesection 8 may be of tubular or box crosssection while the end sectionsmay be channel shape or vice versa. As stated previously, the componentsections or any one of them may be constructed from stainless orrustless steel. Furthermore, the frame including both side rails may bemanufactured in three sparate assemblies, i. e. the complementarysections 7, 8 or 9 of two side rails may be connected together bysuitable cross members as a unit after which the various componentsections of both rails can be united to form the complete chassis frame.By this alternative construction, the intermediate sections 8 ci twoside rails joined by cross braces or the like to form a unit, may becarried in stock, for subsequent assembly with complementary pairs ofsections '7 and 9 of various shapes also joined by cross braces or thelike. In this manner, varying shapes of side rails with differentdegrees of kick-ups and different metallurgical analysis can be built upfrom a more or less stock or standardized intermediate unit.

I claim:

l. An automobile chassis frame including side rails having portionsthereof composed of metal possessing metallurgical structure capable oftaking a body nish from the usual method for finishing body plates andpossessing the requisite elas'ic limits to be serviceable as a frameelement,

., the remaining portions of the chassis rails being of diiierentmetallurgical structure.

2. An automobile chassis frame including side rails each composed of alongitudinal member divided transversely into component parts, saidparts possessing different metallurgical structure and united to form anintegral whole, some of said parts being capable of taking a body nishfrom the usual method for linishing body plates.

3. An automobile chassis frame including side rails each composed of alongitudinal member,

S tion of each rail being a separate section of cold rolled steel andthe other sections being of steel of a higher carbon content, all ofsaid sections of each rail being arranged in alignment and united bybutt-welding the meeting edges of the sections together to form anintegral whole.

5. The combination with an automobile body possessing the usual bodynish; of a chassis frame having the outer surface of the web of aU-shaped channel portion thereof possessing a body finish substantiallyequal to that of the body and exposed exteriorally thereof to form apart of the exterior of the body, the remaining portions of the chassisframe being of different metallurgical structure.

6. An automobile chassis frame including a side rail composed of a pairof separate blankedto-shape end strips having longitudinally curvedlongitudinal edges, and an intermediate substantially straight edgedstrip of cold-rolled steel having its ends corresponding in width to theends of the end strips and having a lower carbon content than the endstrips butt-welded at its transverse edges to the correspondingtransverse edges of the end strips to form a unitary side rail blank,said blank being formed into a channel section to produce a rail havinga kick-up at each end thereof.

7. The method of making automobile chassis side rails consisting ofcutting a stock-strip transversely of its length to provide end sectionshaving their longitudinal edges curved, cutting a second stock-striptransversely of its length to provide intermediate sections, arranging apair of end sections in alignment with' an intermediate section withtheir end edges in abutment, buttwelding said end edges together toprovide a continuous blank with contoured longitudinal edges, and thencold forming such blank into a channel section to provide a side railhaving kick-ups at its ends.

8. The combination with an automobile body having running boards; of achassis frame having side rails, each composed of component channelsections Welded end to end with their anges in longitudinal alignment,the intermediate sections only of the rail being disposed in back of therunning boards and having a metallurgical structure capable of receivinga body finish substantially equal to that of the exterior of the body,and fenders secured to the body and arranged to cover the welded jointsbetween the chassis sections.

9. The combination with an automobile body having running boards, of achassis frame having side rails each composed of component channelsections welded end to end with their flanges in longitudinal alignment,the intermediate sections only of the rail being disposed in back of therunning boards and having a metallurgical structure capable of receivinga body nish substantially equal to that of the exterior of the body,horizontal hangers secured to the lower flange of the intermediatesections, and running boards supported upon said hangers and havingtheir inner longitudinal edges abutting the finished Webs of theintermediate sections.

l0. The method of making automobile chassis side rails consisting ofcutting a sheet transversely of its length to provide end sectionshaving to provide a substantially integral blank with f contouredlongitudinal edges, and then forming said blank into channel section toprovide a side rail having kickups at its ends.

JAMES H. CROWE.

